Calorimeter



Oct. 26, 1965 c. A. SEATON ETAL 3,213,684

CALORIMETER Filed Nov. 27, 1962 3 Sheets-Sheet 1 B R I 0 GE 8 R ECOR DER LL! 7;; a: D D :33 38 u: w n: vm 05 D. D. O

INVENTORS BY WM 212 ATTORN Y5 1965 c. A. SEATON ETAL 3,213,684

CALORIMETER Filed NOV. 27, 1962 3 Sheets-Sheet 3 Fig. 3

INVEN C2 05' Q5 LOEESHTOV g y T Grra 9. l/y iana ATTO R N EY United States Patent 3,213,684 CALORIMETER Clarence A. Seaton, Monroe, and Otto A. Uyehara,

Madison, Wis., assignors, by mesne assignments, to The Swiss Colony, Inc., Monroe, Wis., a corporation of Wisconsin Filed Nov. 27, 1962, Ser. No. 240,261 Claims. (Cl. 73-190) This invention relates to gas calorimeters of the gas Comparison type.

0ne of the problems in prior devices for determining the B.t.u. or heating value of a gas is to obtain an accurate continuous reading or indication of the B.t.u. value of the gas. Such is desirable where gas is being purchased on a basis related to its heating value or where the gas is to be treated in accordance with its heating value. Ambient conditions have seriously alfected prior devices. Also, viscosity differences in the gases affect readings in prior arrangements.

One of the objects of the invention is to provide a calorimeter system that will continuously read B.t.u. or heating value of a gas with accuracy.

Another of the objects of the invention is to provide an accurate heat sensing device.

In one aspect of the invention, gas which is to have changes in heating value or B.t.u. measured has a predetermined volume per unit time fed to the burner of the present invention. Preferably, the gas is fed by a positive displacement pump, such as a reciprocating plunger or piston means. The air supplied to the burner also is accurately fed thereto so that a predetermined volume per unit time is supplied. In one form, a diaphragm senses the pressure on the downstream air side of a needle valve or accurate valve, the valve being moved by a suitable electric motor which may be controlled by an electronic circuit. In one type of circuit, gaseous discharge tubes can be used to control the motor.

The base of the burner is arranged so as to abstract substantially all of the heat from the gas. Primary air and secondary air are supplied to the burner, the air being supplied in more than the required stoichiometric volume. The products of combustion are fed through a zone which is arranged to increase the velocity thereof and cause the products to wipe across the surface of a stove or heat sink apparatus. The products of combustion preferably are passed across or in the vicinity of the mixing chamber of primary air and gas so as to extract further heat therefrom. By so doing, water is condensed so that the higher heating Value will be obtained.

The heat sink or stove arrangement has a heat conducting member which has an end or portion spaced from the hot surface located in a boiler in contact with liquid. The liquid as it is changed to steam or vapor passes upward into a condenser from which it is returned to the boiler. The boiler and condenser are arranged to be kept at constant pressure. Such can be accomplished by using a balloon or other expansible means connected therewith. Thus, the boiler and liquid therein are maintained at substantially constant temperature.

A temperature measuring or responsive means is located in the path of heat transfer between the hot surface of the heat sink and the boiler end of the heat conductor. The temperature responsive means may be in the form of a thermistor means which can be connected to a recording or indicating instrument.

In a preferred form of apparatus, two burners are used which heat separate hot surfaces of the heat sink means or heat conductors, the other ends of the hot surface supports or conductors being located in or adjacent the boiler. A thermistor is located in each path,

the thermistors being connected in a suitable electrical bridge circuit for operating a recorder means indicator, or controller.

Instrument grade gas is fed to one of the burners, such being a standard gas. Calibrating gas of known B.t.u. is fed to the other burner so as to determine the calibration of the instrument. Preferably, at least two calibrating gases should be used, noting or marking on the scale of the recorder, the value of each. Then, the gas to be measured is fed to the burner which previously had the calibrating gas fed thereto. Its relation to the instrument grade gas then can be read on the recorder or indicator. It may be desirable to periodically calibrate the instrument which can be done as described or could be carried out with an automatic programming device if desired.

By using two burners, compensation for ambient conditions will be obtained. It should be evident that since the pressures of the air and gas supplies are held to extremely close tolerances and by using volumetric pumps for the gases, flow of air and gases will remain substantially constant. Thus, any change in heating value or B.t.u. content will result in a change of the amount of heat supplied to its stove or heating zone with a resultant indication. A single burner could be used if arrangements were made to calibrate the instrument sufiiciently often.

These and other objects, advantages and features of the invention will become apparent from the following description and drawings which are merely exemplary.

In the drawings:

FIG. 1 is a diagrammatic view of one form of the invention;

FIG. 2 is a side view, partially in section, of the burners and heat sink system;

FIG. 3 is an enlarged fragmentary sectional view of one of the burners;

FIG. 4 is a section taken along the line 4-4 of FIG. 3; and

FIG. 5 is a schematic view of one of the four-way valves of FIG. 1.

First a description of the overall system will be given. Air supply 10 (FIG. 1) is fed to a primary pressure regulator 1 1, the primary regulator, for example, being of the diaphragm type or equivalent. Air from primary pressure regulator 11 is fed by line 12 to an electronic type pressure regulator 13 which will be described hereafter. The electronic pressure regulator 13 feeds primary and secondary air through lines 14, 15, and needle valves 14A, 15A, respectively, to the lefthand burner 16. Details of burner 16 will be described hereafter.

The lefthand burner 16 in the form illustrated is con nected to the source of instrument gas. The source of instrument gas may be fed from cylinder 21 to primary regulator 22 through a safety cutoff 23, the safety cutoff being operated by a suitable safety switch which is activated when the burner flame is extinguished.

The gas is fed to an electronic pressure regulator 24 which feeds the regulated gas through line 25 to a fourway solenoid valve 26, one example of which is seen in FIG. 5. The four-way solenoid valve 26 when set in one direction will feed gas through line 27 or 28 to cylinder 29 of the hydraulic drive arrangement shown generally at 30. The line 27 or 28 is connected through the solenoid valve 26 to line 31 in accordance with the manner in which the valve is set as a result of the actuation of limit switches (not shown) located at either end of travel of the piston 32 in cylinder 29.

For example, if the hydraulic drive cylinder 33 is moving the cross head 34 in an upward direction, gas will be forced from the upper part of the piston in cylinder 29 through line 28 and solenoid valve 26 to line 31. The hydraulic drive is connected to constant pressure 3 source so as uniformly to reciprocate the cross head. Similarly, when the cross head 34 is moving in the opposite direction, line 27 will feed gas through solenoid valve 26 to line 31.

The collector 35 may comprise a chamber having a diaphragm therein (not shown) for receiving the gas. The purpose of collector 35 is to serve as a flame stabilizer, which is particularly desirable at the beginning or end of the stroke of piston 32 in cylinder 29 so as to smooth out any slight fluctuations which might occur.

The gas from collector 35 is fed through line 36 to the left hand burner through a needle valve 36A. A bleed-off line 37 is controlled by a three-way valve or pet cock arrangement 38 which permits gas to be bled from the circuit.

The unknown gas or the gas to be tested is fed through line 39 through primary regular 40 which is similar to regulator 22 and by line 41 through three-way valve 42. Gas is fed to a safety cutoff 43 and then to an electronic pressure regulator 44. A bleed-off line 45 is controlled by valve 46. The purpose of bleed-off 45 is to permit rapid transfer of the sample to be tested into the circuit. For example, if the source of unknown gas is at a substantial distance from the apparatus, it would take considerable time for it to arrive at the measuring points.

The electronic pressure regulator may take various forms. A diaphragm, not shown, can be connected to the downstream side of feed, the diaphragm controlling a sensing means which in turn operates a reversible motor for controlling a needle valve or other valve in the line. The sensing circuit may include electronic or semiconductor devices for operating motor relays or the motor directly.

Pressure regulator 44 feeds a four-way solenoid valve ,47 which is similar to four-way valve 26 seen in FIG.

5. Valve 47 is connected by pipes or lines 48 and 49 to the upper and lower portions of cylinder 50 which has a piston 51 connected to cross head 34. Limit switches similar to those described for cylinder 29 also actuate four-way solenoid valve 47 so as to permit gas to fill and to be exhausted from cylinder 50 to collector 52, collector 52 being similar to collector 35. Gas is fed through collector 52 through line 53 and needle valve 54 to the righthand burner 20.

The cylinders 29 and 50 and related equipment permit a predetermined volume of gas per unit time to be furnished to the burners.

In order to standardize the instruemnt, a tank of standard gas designated as Gas A in tank or supply 55 is used, and a second standard gas, designated as Gas B in tank 56 is used. Each of these gases can be fed through primary regulators 57 and 58, respectively, to three-way valve 42. Of course, if desirable more than two standard gases can be used with an appropriate valvmg.

In standardizing the instrument, it is desirable first to determine one point on the recording instrument or indicator. Standard Gas A in cylinder 55 is connected to the instrument by turning three-way valve 42 to the cylinder having the gas to be measured, and it is then compared by the instrument to determine a B.t.u. marking or index on the scale or recording instrument corresponding to the known B.t.u. content of the sample in cylinder 55. After this has been measured, three-way valve 42 is turned so as to direct the standard gas in cylinder 56 to the righthand burner which then will determine a second point on the scale or recording instrument.

Inasmuch as the difference in the B.t.u. content of the gases in the two cylinders is known, the recording instrument or scale can be calibrated for the B.t.u. content of these two samples. The relation of the standardizing gases to the unknown gas can be ascertained when the unknown gas again is connected to the righthand burner, such being referenced to the marks or scale just determined.

The purpose of the lefthanded burner 16, or instrument gas burner, is to serve as a compensation for ambient temperature changes and barometric changes. It is possible to use just a single burner of the type described hereafter. Each of the burners has a thermostat, thermistor, or other temperature sensing element connected to a suitable electrical bridge circuit, and it is the output of this circuit which is used to actuate the recording or indicating instrument. It may be desirable in place of the instrument gas in cylinder 21 to provide other means to supply a constant source of heat to the system so as to reflect the ambient conditions and eliminate any errors which might arise through temperature differences in the various electronic pressure regulators of the system.

A description will now be made of a preferred form of burner arrangement, reference being made to FIGS. 2, 3 and 4. The base may be constructed of non-corrosive metal and may have a wall 76 which extends at 77 above floor 78 so as to receive the glass chimney 79 in annular slot 76A. The base has a circular chamber 80 and a mixing chamber 81.

The gas is fed into mixing chamber 81 through line 82. Directing nozzle arrangement 83 is arranged to impart the gas a swirling action within mixing chamber 81. Primary air is fed through line 84 and directing nozzle 85. Secondary air is fed through line 86 into secondary air chamber 87, the secondary air chamber roof 88 having apertures 89 therein.

The gas conducting tube 90 has an exit passage 91 which is adjacent to secondary air cone 92. The flame burns at zone 93 within the interior of chimney 94.

The used products of combustion are fed upwardly and strike plate 95 of the heat sink shown generally at 96. The gases strike the plate and are directed outwardly as shown by arrows at zone 97. The relative area through which the gases pass at zone 97 to the area of exit zone or exhaust passage 98 is approximately identical, or slightly greater, so that no back pressure Will be created within zone 98. The gases have a sweeping action on the plate enhancing heat transfer.

The heat sink 96 may comprise a plate 95 having ci-rcular recess 96A for receiving the top of glass chimney 79. Plate 95 has zone 97D with a passage 97A for reception of a temperature measuring device such as a themistor 97B, which gives an indication of the heat transferred. Cover plate 99 closes the mouth of zone 97D.

A heat transmitting fluid, such as a silicone oil, can be inserted in zone 97D if a more rapid response is desired, and then the thermistor placed therein, the bottom edge 97C thereof being located slightly above the top of cover plate 99.

Heat transmitting bar 100 passes through or is connected to the bottom chamber 101 of condenser arrangement 102 (FIG. 3). The portion 103 of heat transmitting bar 100 which is within bottom or collecting chamher 101 may have apertures 104 therein for the purpose of improving heat transfer. Apertures 104 will eliminate violent eruptions as might be the case if the bar were smooth.

Boiler 105 may have a condensate collector column arrangement 106 which is connected to the bottom of condenser tube 104A. Condenser tube 104A extends upwardly and has cooling fins 105A connected thereto for the purpose of increasing heat transfer.

The upper end of the condenser 104B has a suitable diaphragm means 104C, such as a balloon, for the purpose =of keeping the pressure constant within the boiler 105 and associated parts, the balloon expanding if pres sure tends to build up.

As tliquid, such as water, is condensed in condenser 104B, it will drip downwardly through condenser tube 104A and will first enter cup member 106A, cup member 106A being supported on rod 107 which is suspended from the bottom of condenser tube 104A in any suitable manner so as to leave a passage for water to flow downwardly. Cup 106A has rounded edges 108 at the top thereof and a dished or anguIa-rly disposed bottom surface 109 so that as the liquid collects in cup 106A and runs over the edge 108, it then will drip downwardly across the bottom and again be directed onto rod 107. The downfiowing liquid then passes downwardly into the second cup 110 which has a similar upper edge 111 and bottom surface 112 so that the liquid will be directed therefrom to bottom cup 113. Bottom cup 113 has a similar rounded edge 114 and angularly disposed bottom surface 115 for carrying the condensed liquid back into the liquid in the bottom of boiler 105, the preferred level being illustrated at 117.

The purpose of the cup arrangement is to ensure heat transfer from the cool liquid descending from condenser 104B so that when it again reaches the liquid in the reservoir, it will be heated substantially back to 212 F., or the boiling temperature of the fluid. In this manner, the pressure is kept substantially constant and the liquid is kept at substantially 212 F or the boiling temperature of the fluid, so that a constant temperature will be present in the heat sink system. It also would be possible to provide apertures (not shown) in the bottom of the cups.

Now describing operational details of the burner, the secondary air also serves as primary air in case there is insufi'icient primary air to support combustion. There should be more than the stoichiometri'c amount of air present. There is a relatively large burning zone 93 above the burner tip passage 91 so that there will be excellent mixing of the primary combustion products and the secondary air. Such will cause a complete burning to take place, the products of combustion being thoroughly mixed as they pass through the conical passage 98. The velocity of the products of combustion 1's increased as they pass toward plate 95, the gases then being given a sharp angular turn as they sweep across the bottom of heated surface plate 95. The products of combustion then pass downwardly, heat thereof being transferred through 92A, and at the base of the burner in a regeneration process. Moisture will be condensed in chamber 80. Thus, substantially all of the heat is extracted.

The surface of plate 95 and portion 99 thereof will fluctuate in temperature depending upon the heating value of the gas to be determined or being monitored. The greater the B.t.u. value per cubic foot of gas, the higher will the temperature of the bottom surface of plates 95 and 99 become. The effective cold side of plate 95 is held at the boiling point of water or the liquid being used due to the boiler and condenser arrangement, the heat being transferred from the hot surface of plate 95 through bar 100 to the liquid or water in chamber 101. The temperature responsive means is in the path of heat transfer between the plate 95 and the substantially constant temperature liquid body in chamber 101. The portion of the apparatus receiving the heat may be termed the stove. If it is desired to have a less sensitive temperature recording, the thermistor or other tempearture responsive means can be located at some other place in bar 100.

In order to obtain a more efficient heat transfer path from plate 95 to the thermistor 97B, fluid is used in the passage 97D. However, since the temperature sensing thermistor is surrounded by warm walls it follows the changes without the heat transmitting fluid. As mentioned silicone oil has been found eflicacious although similar high boiling point, inert material can be used. If the well is completely filled, the average temperature of the adjacent zone will be indicated. If only the bottom of the well is filled, then the surface temperature would be read.

It should be apparent that variations can be made in details of construction without departing from the spirit of the invention except as defined in the appended claims.

What is claimed is:

1. In a gas comparison calorimeter, the combination including means for supplying a predetermined volume of gas per unit time to a burner, means for supplying a predetermined volume of air per unit time to a burner, burner means for burning said gas, said burner means receiving said gas and air, heat sink means having a surface area exposed to the products of combustion of said burner means, boiler means conductively connected to said surface area, said boiler means having a liquid therein, condenser means connected to said boiler means for returning condensed liquid thereto, so that said boiler means maintains one end of said heat sink means at substantially constant temperature, temperature responsive means in the path of heat flow from said surface area and said boiler means, and indicating means connected to said temperature responsive means for indicating gas heat value change.

2. In a calorimeter, the combination including means for supplying predetermined volumes per unit time of gas and air, a pair of burner means for receiving said gas and air and burning the same, said burner means having passages directing the products of combustion upwardly, a heat conducting means having surfaces adjacent said passages, said surfaces being located relatively close thereto so as to turn said products of combustion relative to their path from said passages, liquid boiler means connected to said heat conducting means, condenser means connected to said boiler means for returning condensed liquid to said boiler means, said condenser means including spaced cup means for successively receiving condensed liquid as it descends toward said boiler means so as to enhance heat transfer therebetween, and temperature responsive means responsive to temperature changes of said heat conducting means so as to provide an indication of heat value of said gases.

3. In a calorimeter, the combination including means for supplying predetermined volumes per unit time of gas and air, a pair of burner means for receiving said gas and air and burning the same, said burner means having passages directing the products of combustion upwardly, a heat conducting means having surfaces adjacent said passages, said surfaces being located relatively close thereto so as to turn said products of combustion relative to their path from said passages, liquid boiler means connected to said heat conducting means, condenser means connected to said boiler means for returning condensed liquid to said boiler means, said condenser means,

including a plurality of vertically spaced cup means receiving condensed liquid as it descends toward said boiler means, said cup means receiving liquid and directing it downwardly along the sides thereof so as to enhance heat transfer therebetween, and temperature responsive means responsive to temperature changes of said heat conducting means so as to provide an indication of heat value of said gases.

4. A calorimeter as set forth in claim 3, wherein said vertically spaced cup means 'are of increasing diameters from a small upper one to a large lower one.

5. In a gas comparison calorimeter, the combination including means for supplying a predetermined volume of gas per unit time, means for supplying a predetermined volume of air per unit time, burner means for receiving said gas and air, heat conducting means having a surface zone against which products of combustion of said burner means impinge, gas and air mixing chamber means adjacent said burner means, chimney means directing products of combustion after they have impinged on said surface zone to said mixing chamber means so as to transform heat thereto and condense liquid, boiler means connected to said heat conducting means, condenser means connected to said boiler means for returning condensed liquid from said boiler means back to said boiler means so that the portion of said heat conducting means connected to said boiler means will remain at substantially constant temperature, and temperature responsive means located in heat transfer liquid in wells in said heat conducting means for measuring heat transfer between said surface zone and said boiler means.

References Cited by the Examiner UNITED STATES PATENTS Kessling 73374 Parr 73-190 Johnson 73190 Schmidt 73-190 Schmidt 73-190 Bortin 13764 X Parnes et a1 126-381 Kindred et a1 73190 X 8 OTHER REFERENCES Harvalik, Z. V.: A Modified Fitch Thermal Conductivity Apparatus. In the Review of Scientific Instruments -18(11),p. 815, November 1947.

Obert, E. F.: Internal Combustion Engine, Scranton, Pa. International Textbook Co., 1950, FIGS. 17-19, p. 589.

Obert, E. F.: Internal Combustion Engineer, Scranton, Pa. International Textbook Co., 1950, page 91.

RICHARD C. QUEISSER, Primary Examiner.

JOSEPH P. STRIZAK, Examiner. 

1. IN A GAS COMPARISON CALORIMETER, THE COMBINATION INCLUDING MEANS FOR SUPPLYING A PREDETERMINED VOLUME OF GAS PER UNIT TIME TO A BURNER, MEANS FOR SUPPLYING A PREDETERMINED VOLUME OF AIR PER UNIT TIME TO A BURNER, BURNER MEANS FOR BURNING SAID GAS, SAID BURNER MEANS RECEIVING SAID GAS AND AIR, HEAT SINK MEANS HAVING A SURFACE AREA EXPOSED TO THE PRODUCTS OF COMBUSTION OF SAID BURNER MEANS, BOILER MEANS CONDUCTIVELY CONNECTED TO SAID SURFACE AREA, SAID BOILER HAVING A LIQUID THEREIN, CONDENSER MEANS CONNECTED TO SAID BOILER MEANS FOR RETURNING CONDENSED LIQUID THERETO, SO THAT SAID BOILER MEANS MAINTAINS ONE END OF SAID HEAT SINK MEANS AT SUBSTANTIALLY CONSTANT TEMPERATURE, TEMPERATURE RESPONSIVE MEANS IN THE PATH OF HEAT FLOW FROM SAID SURFACE AREA AND SAID BOILER MEANS, AND INDICATING MEANS CONNECTED TO SAID 